Technical Field
The present disclosure relates to a converter. More particularly, the present disclosure relates to a voltage clamp circuit in a converter.
Description of Related Art
Conventionally, a converter having multi-level output is widely applied in related fields such as solar inverter, uninterruptible power supply (UPS), power conditioning system (PCS), etc.
The converter usually includes devices such as switches, in which the switch on a current commutation path is switched on and off alternately to perform a current commutation operation.
However, parasitic inductance usually exists in the current path, and thus, in a transient period of the aforementioned switch being switched on and off alternately, the existence of the parasitic inductance results in that the aforementioned switch sustains a higher voltage, and even when the aforementioned switch is switched off, voltage spikes are generated to affect the aforementioned switch. For example, when an input voltage of the converter is 380 Volts, the voltage spikes may reach up to 600 Volts and is much higher than a rated voltage sustainable for the switch, in the transient period of the aforementioned switch being switched off. As a result, damages to the switch are caused such that the converter cannot operate normally.